The present study analyzed and compared the daily consumption of foods of animal origin in eleven communities of the Lower Amazon, Trombetas and Purus Rivers, representing three different management systems and levels of conservation in the Brazilian Amazon. All food items of animal origin were weighed by at least 10% of the families in the study communities during a week in each period of the flood cycle between 2006 and 2008. Fish was the most important food, and was consumed during six days of the week, with an average rate of 169 kg.person(-1).year(-1). Game was second in importance, with 37 kg.person(-1).year-(1). This yearly rate of fish consumption is one of the highest in the world and is almost double the minimum recommended by the World Health Organization. The dietary patterns reflect both the isolation of the communities from large urban centers and the better preservation of the local environments due to the existence of protected areas. Environmental degradation may thus have effects on the health and food security of local populations. The study emphasizes the need for the implementation of public policies and participative management initiatives.

Amazon floodplains have a long history of exploitation of crocodilians, particularly of large species such as the black caiman (Melanosuchus niger) and spectacled caiman (Caiman crocodilus). Historically, legal but uncontrolled trade resulted in a drastic reduction of wild populations of both species, which eventually led to the collapse of the commercial trade. In 1967, prohibition of commercial use of wild fauna through changes in Brazilian and international laws allowed caiman populations to slowly recover across much of their original range. Several studies on caiman populations greatly improved knowledge about the species, offering scientific bases for crocodilian management in the wild. Although protective legislation should only be altered using extreme caution, the creation of Sustainable Development Reserves (SDR) at the end of last century made it possible to manage wildlife for commercial purposes, albeit under strict population monitoring regimes. This category of protected area was established to improve welfare of local communities and strengthen their participation in conservation. Along with involvement in caiman monitoring programs, the engagement of local hunters and buyers is essential for participatory management plans. Even with development of SDRs, monitoring of crocodilian populations is still restricted to a few State Reserves, and traditional knowledge of stakeholders has been insufficiently incorporated into management and monitoring activities. We believe that stronger participation of local actors can help to improve the experimental harvesting initiatives that have been carried out thus far by local authorities. Community-based monitoring programs, which reflect local reality, are being developed in a simple and cost-effective way.

In the present study a unique dataset on population abundance in various community-based management (CBM) and non-CBM areas is analysed to address the question of whether CBM can recover overexploited populations of Arapaima sp. in river-floodplain ecosystems. All non-CBM areas possessed depleted Arapaima sp. populations with a mean density of 001 individuals ha(-1) . Arapaima sp. population densities in all CBM areas changed over time from depleted to overexploited or well managed status, with a mean rate of increase of 77% year(-1) . Rates of Arapaima sp. population recovery in CBM areas differed, probably reflecting differences in ecosystem productivity and compliance with management regulations. These results indicate that CBM schemes can be effective tools for the recovery and conservation of fish populations with non-migratory life cycles in tropical river-floodplain ecosystems.